perf(rendering): reconcile only changed attachments

docs/ISSUES.md

@@ -328,7 +328,7 @@ graph corrupts collision state, which is worse than the allocation.
 
 ## #238 — EquippedChildRenderController ticks twice per frame with six ToArray snapshots
 
-**Status:** OPEN
+**Status:** DONE — 2026-07-25, Modern Runtime Slice H-a3
 **Severity:** MEDIUM
 **Filed:** 2026-07-24
 **Component:** render / live entities
@@ -350,6 +350,14 @@ the ordering and skip the redundant recomposition instead. Plan Slice H-a.
 **Files:** `src/AcDream.App/Rendering/EquippedChildRenderController.cs:265-310,1421-1429`;
 `src/AcDream.App/Update/LiveObjectFrameController.cs:204,241`.
 
+**Resolution:** Both required authority boundaries remain. The first is still a
+complete parent-first pose pass; the post-network boundary now compares the
+exact parent's pose version, identity, visibility, and cell and recomposes only
+changed branches. Publishing a changed child dirties its descendants naturally
+within the same parent-first walk. Per-heartbeat pending dictionaries use
+retained typed snapshots instead of arrays. Evidence:
+`docs/research/2026-07-25-slice-h-a3-attached-pose-reconcile.md`.
+
 ---
 
 ## #239 — Inbound net path allocates 3-4 arrays/objects per packet

docs/plans/2026-07-25-modern-runtime-slice-h.md

@@ -62,7 +62,7 @@ cooldown step.
 Landed evidence:
 [`../research/2026-07-25-slice-h-a2-cooldown-scope.md`](../research/2026-07-25-slice-h-a2-cooldown-scope.md).
 
-### H-a3 — equipped-child transition work
+### H-a3 — equipped-child transition work — COMPLETE
 
 1. Preserve both frame ordering points: pre-network presentation and
    post-network spatial reconciliation have different authority boundaries.
@@ -77,6 +77,9 @@ Landed evidence:
 Gate: equip, unparent, reparent, pose loss, rollback, delete, GUID reuse, and
 subtree-withdrawal suites preserve exact event and resource counts.
 
+Landed evidence:
+[`../research/2026-07-25-slice-h-a3-attached-pose-reconcile.md`](../research/2026-07-25-slice-h-a3-attached-pose-reconcile.md).
+
 ### H-a4 — diagnostics and frame scratch
 
 1. Reuse one synchronous `RetailPViewFrameInput` owned by

docs/research/2026-07-25-slice-h-a3-attached-pose-reconcile.md

@@ -0,0 +1,45 @@
+# Slice H-a3 — equipped-child post-network reconciliation
+
+## Preserved ordering
+
+Retail live-object presentation still has two authority boundaries:
+
+1. the complete parent-first attachment update after animation;
+2. post-network spatial reconciliation after accepted inbound mutations.
+
+The second boundary was not deleted or delayed.
+
+## Change
+
+`EntityEffectPoseRegistry` now carries a monotonic change version for the
+current pose-owner lifetime. It advances only when root, indexed parts, part
+availability, or cell changes.
+
+Each attached projection remembers the exact parent entity, pose version,
+draw/ancestor visibility, and parent cell used for its last composition.
+
+- The animation-order pass remains a complete parent-first walk.
+- The post-network pass keeps transition retries but skips a child whose
+  remembered parent presentation is unchanged.
+- A changed root recomposes its direct child; publishing that child's pose
+  advances its version, so descendants update later in the same parent-first
+  pass.
+- Hidden/NoDraw ancestry and cell changes participate even when the geometric
+  pose itself is unchanged.
+- Pose failure still withdraws the same complete subtree.
+
+The per-frame transition retry path no longer allocates dictionary `ToArray`
+snapshots. It copies key/value pairs into retained typed scratch lists, keeping
+the old snapshot-before-callback semantics.
+
+## Gate
+
+- Existing equip/unparent/reparent/rollback/pose-loss/teardown tests pass.
+- A root → child → grandchild test proves unchanged post-network reconcile
+  performs zero compositions and a changed root performs exactly two in
+  parent-first order.
+- 1,000 stable post-network reconciles allocate zero managed bytes on the
+  calling thread.
+
+Release gate: 3,783 App tests passed / 3 skipped; 8,267 complete-solution
+tests passed / 5 skipped.